This application relates to an endoscopic video imaging system for transmitting communication signals and illuminating light along a single cable between a camera control unit and a camera head.
The field of video endoscopy, to which the present invention generally relates, includes medical diagnostic and therapeutic disciplines that utilize endoscopes to penetrate and view otherwise inaccessible body cavities utilizing minimally invasive surgical procedures. Coupling of video imaging cameras (incorporating solid-state imagers) to endoscopes, for image reproduction, has become standard within the field. Endoscopic video cameras (hereinafter referred to as “camera heads”), are most advantageously small and lightweight for ease of use by medical personnel, and typically incorporate either single or multiple solid-state imagers. Some special purpose endoscopes have integrated (built-in) solid-state imagers, which do not facilitate direct viewing of internal body cavities by medical personnel without an accompanying video imaging system and display. To achieve the desired size and weight, camera head and/or integrated endoscope-camera assembly electronics are typically separated physically from the majority of circuitry required to process and output high-quality, color video images.
In known video imaging systems, interconnection between camera control units (“CCUs”) and camera heads is achieved by means of a cable, with usually one cable end permanently fixed to the camera head, while the other cable end is detachably connected to the CCU using a connector. Similar to the camera head itself, it is advantageous that cables be small in diameter and lightweight, but rugged enough to withstand repeated sterilization, accidental gurney wheel “run-over” and the like.
Most cables for endoscopic video cameras include a fiber optic light guide for illumination, the fiber optic light guide being separately distinct from the cable transmitting electronic video signals. Because the operating room has limited space, extra medical equipment typically creates a substantial inconvenience for medical personnel.
Existing interconnections between camera heads and CCUs typically comprise dedicated parallel wires to provide greater data carrying capacity. It is meant by “dedicated parallel wires” that each specific signal is transmitted by means of an individual wire, either single for power and control signals or shielded coax for image data, between a camera head and CCU. However, a disadvantage of providing dedicated parallel wires is that typically twenty to thirty separate lines are required to control, energize and receive image data from camera heads, with most signal lines requiring a dedicated connector pin. The more channels required, the greater the diameter, size and corresponding weight of the cable bundle. The larger this bundle becomes, the more likely it is to interfere with medical personnel's use of the video imaging system. Moreover, utilizing dedicated parallel wire type cabling is undesired when additional functionality is required and added to either the camera head or CCU. To accommodate this new functionality, additional wiring must be incorporated in the cable bundle, requiring equipment redesign and subsequent purchase by customers. Also, as video imaging systems develop, CCUs are becoming programmable for compatibility with various types of camera heads, are adding new control features and are processing different types of video signals.
Typically a combined optical electrical connector is provided with optical and electrical components that can move relative to one another within the body of the connector. Disadvantageously, correct and precise adjustments of the respective components are difficult and, time consuming, where the poor connection often results in poor system performance. In addition, the separate cables for transmitting illuminating light and information may become tangled thereby becoming an inconvenience for the user.
It is therefore desired to provide a video imaging system that utilizes relatively few channels in order to reduce the size and corresponding weight of the cable, while still maintaining high video image quality.
It is also desired to provide a video imaging system that incorporates the light source guide for illumination into a single cable with the channel transmitting information between the camera head and camera control unit.
It is further desired to provide a video imaging system that has a rugged cable assembly that will not be damaged by day-to-day use in the operating room. It is still further desired to provide a connector where electrical and optical components are in a fixed spatial relationship to one another and are integrated into a single connector so as not to tangle with one another.